%0 Journal Article
%T Optimization of Growth Conditions to Identify the Superior <i>Bacillus</i> Strain Which Produce High Yield of Thermostable Alpha Amylase
%A Witharanage Wasana Prasadini Rodrigo
%A Lakmi Samodha Magamulla
%A Morawakage Sajith Thiwanka
%A Yapa Mudiyanselage Shashika Madhuwanthi Yapa
%J Advances in Enzyme Research
%P 1-22
%@ 2328-4854
%D 2022
%I Scientific Research Publishing
%R 10.4236/aer.2022.101001
%X Thermostable <i>¦Á</i>-amylases
hold a very important place in commercial industrial applications in Sri Lanka.
Therefore, <span style=\"font-size:10.0pt;font-family:;\" \"=\"\">the </span><span style=\"font-size:10.0pt;font-family:;\" \"=\"\">main aim of this study was to identify superior <i>Bacillus</i> strain and optimize growth conditions that could yield
high <i>¦Á</i>-amylase production. Three <i>Bacillus</i> strains, <i>B. amyloliquefaciens</i> ATCC 23350, <i>B. licheniformis</i> ATCC 14580 and <i>B.
megaterium</i> ATCC 14581 were used for the study. Shake flask culture experiments
were conducted to identify the effect of various fermentation conditions such
as growth temperature, incubation period, carbon source, nitrogen source,
initial pH and carbon concentration on extracellular <i>¦Á</i>-amylase production. DNSA assay was carried out to determine the enzyme
activity. The highest temperature for enzyme activity was reported by <i>B. licheniformis </i>at 85¡ãC, followed by<i> B. amyloliquefaciens</i> at 75<span style=\"font-size:13.3333px;white-space:normal;\">¡ã</span>C and <i>B. megaterium</i> at 45<span style=\"font-size:13.3333px;white-space:normal;\">¡ã</span>C. Both <i>B. amyloliquefaciens</i> and <i>B. licheniformis </i>were able to give their
optimum enzyme production at 37<span style=\"font-size:13.3333px;white-space:normal;\">¡ã</span>C, while <i>B.
megaterium</i> at 30<span style=\"font-size:13.3333px;white-space:normal;\">¡ã</span>C in 150 rpm with initial pH of 7. <i>B. licheniformis</i> and <i>B. amyloliquefaciens</i> gave their optimum yield of the enzyme after 48 h of incubation while <i>B. megaterium</i> gave after 24 h of
incubation. Among the carbon sources tested cassava starch was able to give the
highest enzyme production. For <i>B.
amyloliquefaciens</i>, the highest yield of the enzyme was obtained with 2% of
starch, tryptone as a nitrogen source and initial pH of 7. Maximum enzyme
production for <i>B. licheniformis</i> was
obtained with 1.5% of starch, KNO<sub>3</sub> as a nitrogen source and initial
pH of 6. For <i>B. <span>megaterium</span></i><span> 1% of starch,
tryptone and pH 7.5 induced the optimum</span> <i>¦Á</i>-amylase production. According to the results obtained, <i>B. amyloliquefaciens</i> is the highest
thermostable alpha amylase producer. However, according to the industrial
requirement</span><span style=\"font-size:10.0pt;font-family:;\" \"=\"\">,</span><span style=\"font-size:10.0pt;font-family:;\" \"=\"\"> <i>B. licheniformis</i> can also be
used as an enzyme producer due to its stability in higher
%K Thermostable
%K &lt
%K i&gt
%K ¦Á&lt
%K /i&gt
%K -Amylase
%K &lt
%K i&gt
%K Bacillus&lt
%K /i&gt
%K Strain
%K Fermentation
%K Incubation Period
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=115770